Tom Riddle

Is this the face of a murderer, a tyrant? If you read JK Rowling's Harry Potter series, you know that Tom Riddle is the orphan whom Dumbledore retrieves to the magical world. Riddle becomes, according to Dumbledore, perhaps Hogwarts' most brilliant student ever.

Despite Riddle's enormous talent, Dumbledore suspects from the beginning that he's damaged beyond repair. Riddle comes from a temendously powerful but paraniod bloodline: Slytherin. He uses his Hogwarts years to learn where power resides and how to seek it.
He eventually takes on a new name - Lord Voldemort - then terrorizes the wizarding world.

Like several of his followers, Lord Voldemort can be classy and charming. He seldom manages to be boring. His appeal is captured by Ollivander,the wand maker, who explains that Voldemort did "...great things. Terrible things...but great."

To me, Riddle exemplifies the danger of being so brilliant, you can live from your talent alone. Dumbledore, while acknowledging Riddle's brilliance, points out more than once Riddle's general lack of understanding.

Here he is, the young Riddle of film, played by Frank Dillane (Riddle was played by various actors depending on his stage of life). I've never seen the movies myself, though I've read all the books to my children.